While honoree Bob Colacello addressed the New York Academy of Art’s Tribeca Ball Monday, Peter Marino inadvertently provided some side entertainment for the fun-loving crowd. The architect, who routinely wears black leather biker gear, had a slight wardrobe malfunction, spies said, which set off a titter around the tables. “When Peter sat in his tight leather pants, his butt was showing,” said a spy. “Soon people got out their iPhones and started taking pictures and passing them around. Bob may have had no idea why some people were cracking up.” At the benefit for the school Andy Warhol founded, Colacello gave “a moving speech as if Andy was in the room” for guests including Joan Rivers, Chelsea Handler, Carla Gugino, Cindy Sherman, Diane von Furstenberg, Larry Gagosian, Carolina Herrera and Francesco Clemente. An aerialist served Nicolas Feuillatte bubbly while Olivier Sarkozy entertained much-younger gal pal Mary-Kate Olsen by “doing a little dance in front of her” at the Van Cleef & Arpels-sponsored bash.